The word “improvements” herein shall include appurtenant water rights and all improvements placed upon the land in compliance with Section 19-7-51 N.M. Stat. Ann., and shall include those appurtenant water rights and improvements placed upon the land prior to March 1, 1955, whether or not the value be in excess of the amount prescribed by Section 19-7-51 N.M. Stat. Ann.. Appurtenant water rights and improvements placed upon the land after March 1, 1955 but prior to March 1, 1975 may be included by the commissioner in accordance with rules and regulations adopted by the commissioner.